1. Field of the Invention
This invention relates in general to evaporative cooling systems and in particular to a cooling pad for a greenhouse utilizing porous rocks as the medium.
2. Background of the Invention
In the warmer parts of the country, greenhouses must have cooling for the hot months of the year. Medium and large size greenhouses normally have large exhaust fans located on one wall for drawing air through an aperture or window in the opposite wall. To cool the air, normally a large, vertical cooling pad will make up a large part of the opposite wall. There are various types of cooling pads, but in general, they employ an organic cellular or fibrous wood base material through which the air is drawn. Water is circulated to the top of the pad where it drips through the pad to cause evaporation and cool the air passing through the pad.
While these pads are able to cool the air, they deteriorate, clog and require replacement periodically. Also, they reduce the air flow. Moreover, it would be advantageous to have increased evaporation to increase the cooling and lower the temperature through the greenhouse.
A porous inorganic medium such as lava rock is sometimes placed on the ground within the greenhouse. The rocks are moistened to increase humidity in the greenhouse. To applicant's knowledge, these rocks have never been used in a position where air could be drawn through them.